#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(int argc,char* argv[])
{
    if(argc!=4){
        printf("Usage: %s [-a -s -m -d] first_data second_data\n",argv[0]);
    }
    int a = atoi(argv[2]);
    int b = atoi(argv[3]);
    if(strcmp(argv[1] ,"-a") == 0){
        printf("%d+%d = %d\n",a,b,a+b);
    }
    else if(strcmp(argv[1],"-s") == 0){
        printf("%d-%d = %d\n",a,b,a-b);
    }
    else if(strcmp(argv[1],"-m") == 0){
        printf("%d*%d = %d\n",a,b,a*b);
    }
    else if(strcmp(argv[1],"-d") == 0){
        if(b == 0){
            printf("error!!!\n");return 0;
        }
        printf("%d/%d == %d\n",a,b,a/b);
    }
    return 0;
}
